This authoritative resource on the proliferation of nuclear, chemical, and biological weapons and their delivery systems reflects the rapidly changing international environment. The authors use government and nongovernmental sources to present the risks posed by those weapons, as well as the successes and failures of international efforts to prevent their spread. The book is divided into five major sections: assessments and weapons, declared nuclear-weapons states, non-Nuclear Proliferation Treaty nuclear-weapons states, two hard cases (North Korea and Iran), and nonproliferation successes. Each country is treated separately. The book contains informative maps and charts summarizing capabilities and risks associated with the weapons, as well as a series of useful appendices. It is an easy-to-use resource for experts, students, journalists, and the interested public. This edition is a revised and expanded version of the original work published in 2002.